Stud driving tool with trigger-tilt breech



ug- 29, 1967 E. BURTSCHER ETAL 3,338,496

STUD DRIVING TOOL WITH TRIGGE'R`TILT BREECH Filed April 21, 1965 3 Sheets-Sheet 1 owmmwuw wksn @N NK N Wm. QN .EN

INVENTORS ELW//V BURTSCHER ELMR SATL/NER BY HEL/V07' @EST-FLE M, #MMC ATTORNEYS' Aug 29, 1967 E. BURTSCHER ETAL 3,338,495

STUD DRIVING TOOL WITH TRIGGER-TILT BREECH Filed April 2l, 1965 3 Sheets-Sheet 2 w. w n m E. BURTSCHER ETAL 3,338,496

STUD DRIVING TOOL WITH TRIGGER-TILT BREECH Aug. 29, 1967 3 Sheets-Sheet 3 Filed April 2l, 1965 m .ma

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INVENTORS ELW//v au/Prscf/ER LM/4R @Anm/5R BY MS2/1407 offiz-AME MQMLMI ATTORNEYS United States Patent O 3,338,496 STUD DRIVING TOOL WITH TRIGGER-TILT BREECH Elwin Burtscher, Voralberg, Austria, Elmar Batliner,

Fursteutum, Liechtenstein, and Helmut Oesterle, Voralberg, Austria, assignors to Hilti AG, Schaan, Liechten- This invention relates to a tool for driving studs or the like into hard receiving materials, such as concrete and iron, by means of a thrust piston driven by a propellant gas charge expanding in a chamber disposed at an angle, preferably at substantially a right angle, to a cartridge chamber, and more particularly to a handle and a trigger mechanism for such a tool.

In tools of this type, the breech may be arranged in a handle which is mounted to be slidable in a direction parellel lto the longitudinal axis of the device. To assure rapid ejection of the cartridge after ring and easy insertion of a new cartridge, it is necessary to provide suicient access to the cartridge chamber by leaving a considerable amount of free space between its opening and the handle. Experiments have shown that reasonably rapid replacement of cartridgescan be assured if the handle and breech can be moved at least about 5 cm. from the opening of the cartridge chamber. That is a relatively long displacement and requires use in the tool of relatively long restoring springs which, in turn, require a considerable amount of space. Thus, the size of these tools must be increased, making them cumbersome, although they are preferably intended for one-handed use. Furthermore, either a special latch is needed to hold the handle in the displaced position against the spring force or the operator must hold the handle with one hand while trying to load the tool with only one free hand.

It is an object of the present invention to provide an improved stud driving device of the type described having the advantages of speed and simplicity of handling, especially for reloading cartridges, as well as optimum safety.

In accordance with this invention, a tool is provided having a breech, or closure, -for the cartridge chamber installed in, and as part of, a handle which is pivotally arranged so that it can be tilted on a supporting member of the tool. The swingability of the handle carrying the breech provides the advantage that no lateral displacement of the breech, which increases the size of the tool, is required. Furthermore, the handle is easily operated with minimum expenditure of force, for instance, by merely swinging it open after releasing a snap breech lock, e.g., by a sharp blow against the handle, or swinging it closed to trip automatically the breech lock. When the handle is swung open, there is ample clearance for easy access to the cartridge chamber.

The cartridge chamber breech is preferably locked by a snap breech lock to the supporting piece when the -tool is in tiring position. For that purpose, the handle has a pivoted, spring-loaded lever which upon closing of the device engages a projection on the main supporting member of the tool against the action of the spring. When the trigger is pulled to re the tool, an abutment on the trigger engages the lever to prevent it positively from pivoting and unlocking the handle carrying the breech. Thus, the automatically interlocking snap breech lock can be employed in a simple manner without additional action by the operator during the firing process to preclude opening of the breech when the tool is tired. Furthermore, to open the handle to reload the device, no manual unlocking of the'snap lock is necessary because the interlock is opened lCe in a positive manner by releasing the trigger. A sharp blow to the handle releases it.

According to another embodiment of the invention, the handle has a cartridge ejector actuated by swinging open the handle. The ejector is a lever swingably supported by a pin on the supporting member. It engages part of the rim of a cartridge in the cartridge chamber and is arranged with the handle so that during the opening movement of the handle, a nipping member imparts a swinging motion to the ejector lever to extract the cartridge from the cartridge chamber. Thus, dependable and automatic ejection of the cartridge is assured merely by opening the handle, even if the tool is pointed downwardly so that the longitudinal axis of the cartridge chamber and the direction of ejection of the cartridge are horizontal. The handle acts as a lever to import force to the ejector upon opening of the handle to assure that the cartridge will be pulled out of its chamber. Experience has shown that these advantages contribute greatly to the convenient operation of the device.

The invention can be further understood by referring to the accompanying drawings in which embodiments of the invention are shown by way of example and in which:

FIGURE l is an elevation partly in section and shows a stud driving tool, of the type described, in its inoperative condition;

FIGURE 1A is a perspective showing important elements of the tool and their relationship to one another;

FIGURE 2 shows the tool of FIGURE l in firing position with the breech locked;

FIGURE 3 shows the tool of FIGURE l during opening of the handle; and

FIGURE 4 shows a detail of the cartridge ejector of the tool during closing of the handle.

FIGURES 1 and 1A show a tool having a supporting member 1 on which a removably fastened tube 2 serves as a housing. The tube 2 has a slot in one side whose edges 2a pass slidably along grooves 1a on each side of the supporting member 1 to mount the tube on the supporting member. The supporting member 1 has a bearing pin 3 by which a handle, designated generally by the numeral 4, is pivotally secured. A sleeve 5 within the housing 2 is fastened to the supporting member 1 and serves as a propellent gas chamber. The sleeve 5 preferably is an integral part of the member 1. An opening 6 in the supporting member 1 passing through the wall of the sleeve 5, preferably at substantially a right angle to its longitudinal axis, serves as a cartridge chamber 6 for a cartridge 6a.

At the forward end of the tool, to the left as seen in FIGURE 1, is a "guide 7 with an axial bore for a stud (not shown) to be driven by the tool. The guide 7 is carried by a collar 9 which projects :from and is slidably mounted in the housing Z. A spring 10 within the housing 2 .biases the collar 9 and guide 7 away from the sleeve 5. A thrust piston 8 in the collar 9 has one end slidably supported in the guide 7 and the other end adapted to enter srlidably the sleeve 5 when the tool is in the tiring position, Le., as sho-wn in FIGURE 2, by telescoping the guide 7 and collar 9 into the housing 2. At the end of the tool opposite the guilde 7 is a recoil damping mass 11 s-lidably mounted in the housing 2 and having a pistonlike end 11a adapted to extend into the sleeve 5. A spring 12 between the mass 11 and a housing `closure cover 13 biases the -mass 11 toward the sleeve 5. Details and the operation of these elements are described a'nd illustrated more 'fu'lly in copending application Ser. No. 448,076 led Apr. 14, 1965.

The handle 4 has a solid supporting Ipart 15, generally shaped like a hand grip, the top of which is contiguous to the support member 1 lorf the tool and fonrns the breech 'for the cartridge chamber 6. The handle supporting part 15 is pivoteid on the pin 3 and carries a pin 16 on which a lever 17 is swingably mounted. The lever 17 has two arms 17a and 17b. A spring around the pin 16 applies a counter-clockwise force to the lever 17. The arm 17a cooperates with a nose 19 projecting from the supporting member 1 to form a snap breech lock under the action or the spring 18 which presses the arm 17a against the nose 19 A trigger 26 in the front olf the handle 4 is swingably mounted on a pin 21 carried by the handle supporting part 15. The trigger 20, in turn, has a pin 22 on which two levers 23 and 26 are pivotally supported. One lever 23 is |biased by a spring 24 against a firing pin 25 'within the handle. The lever 23 `bears against a flange 25a of the firing pin 2,5 'when the trigger is pulled back Iand pushes the pin 25 downwardly until the lever 23 slides oft' the flange, releasing the pin 25. The other arm 26 cooperates with a recess portion 11d in the slot 11C in the recoil damping mass 11 to act as a safety. When the trigger 20 is pulled back, the arm 26 moves upwardly through an opening 1b in the supporting member 1. The arm 26 will strike the under side olf the recoil damping mass 11 and will be stopped, preventing further motion of the trigger necessary to release the firing pin 25, unless the recoil damping mass 11 is in the firing position so that the recess in the mass 11 is in line with the arm 26 to provide a clear path for continued upward movement of the arm 26. FIGURE 2 illustrates those elements in the firing position, and the firing pin about to be released by the lever 23'.

It willl be noted also that, in the firing position, the upper edge 20a of the trigger 20 abuts under the arms 17h of the breech lock lever 17. The edge 20a prevents downward movement olf the arm 17b which would disengage the other end 17a or' the lever 17 from the nose 19 to open the llock. Thus, the breech is positively precluded from opening during firing orf the tool by an interlocking of the trigger 20 with the breech lock. Return orf the trigger 20 to its initial position, shown in FIGURE 1, move the abutment 2da away from the arm 17 b so that the handle 4 can be opened by sa slight blow sufficient to overcome the spring 18 holding the lever 17 A cartridge ejector 31 inthe form of an L-shaped llever having the arms 31a and 31b is mounted on the supporting member 1 of the tool by a pin 30. The arm 31a debouohes into the cartridge chamber 6 when the handle 4 is yclosed and rforms a portion of the mouth of the cartridge lchamber 6. The end of the arm 31a is shaped to grasp: partially the rim of a cartridge inserted in the chamber. The ejector 31 is `actuated during opening of the handle 4 by a cam 35 pivoted on a 4pin 33` projecting from the handle support part 15. A spring 34 applies a counter-clockwise force to the cam 35 to hold it in the position shown in FIGURES l, 2 and 3, which position is limited by a stop 28 in a section of the wall 2.8 ott the handle support part 15. As the handle 4 is opened, the cam 35 engages the ejectors hook-like arm 31h in the cams path ot movement and turns the ejector 31 to remove the cartridge 6a from the chamber v6, as shown in FIGURE 3. During closing of the handle 4, as shown in FIGURE 4, the cam 35 is turned clockwise against the spring 34 by the arm 31b of the ejector 31 to permit passage of the cam 35 thereby.

It is to be understood that numerous changes and modifications of the embodiments illustrated can be made by persons skilled in the art without departing `from the scope of the invention as defined in the appended claims.

We claim:

1. A stud ydriving tool comprising a support member and a housing, means for driving a stud carried by said support member comprising a thrust piston and la propellent gas chamber, a cartridge chamber in said support member opening into said propellent gas chamber, a handle pivotally attached to said support member, a breech 'for said cartridge chamber carried by said handle, said breech adapted to cilose said cartridge chamber when said handle is in a first position and adapted to be moved away from said cartridge chamber by swinging said handle about its pivot away from said first position, and firing means carried by said handle for firing a cartridge in said cartridge chamber when said handle is in said first position.

2. A stud driving tool as defined in clai-m 1 wherein the axis of said cartridge chamber is substantially perpendicular to the axis of said propellent gas chamber.

3. A stud :driving tool as defined in claim 1 further comprising a nose projecting from said support member and la lever pivoted on said handle, said lever having an arm Iadapted to engage said nose when said handle is in said first position to lock said handle in that position.

4. A stud driving tool as defined in claim 3 wherein a spring biases said lever against said nose.

5. A stud driving tool as defined in claim 3 wlherein said lever has a second arm extending therefrom and said firing means includes a trigger carried by said handle adapted to engage said second arm when being pulled to fire said tool to prevent pivoting of said lever, thereby positively interlocking said first lever arm against said nose.

6. A stnd driving tool as defined in claim 5 wherein said trigger has a shoulder abutting said second arrn when said trigger is pulled.

7. A stud driving tool as defined in claim 1 [further comprising a cartridge ejector means movably mounted on said support member, and ejector actuating means and carried on said handle and adapted to actuate said cartridge ejector means when said handle is swung away lfrom said rst position.

8. A stud driving tool as defined in claim 7 wherein said cartridge ejector means is pivotal-ly mounted on said support member, has an arm extending to and forming part 'of the outer periphery of said cartridge Achamber to engage the rim of a cartridge placed therein, and has a second arm adapted to engage said ejector actuating means.

9. A stud driving tool as defined in claim 7 wherein said ejector actuating means -is a cam pivotally mounted on said handle adapted to engage and actuate said cartridge ejector means when said handle is swung away from said first position and to pivot and move past said cartridge ejector means when said rhandle is swung to said first position.

No references cited.

GRANVILLE Y. CUSTER, IR., Primary Examiner. 

1. A STUD DRIVING TOOL COMPRISING A SUPPORT MEMBER AND A HOUSING, MEANS FOR DRIVING A STUD CARRIED BY SAID SUPPORT MEMBER COMPRISING A THRUST PISTON AND A PROPELLENT GAS CHAMBER, A CARTRIDGE CHAMBER IN SAID SUPPORT MEMBER OPENING INTO SAID PROPELLANT GAS CHAMBER, A HANDLE PIVOTALLY ATTACHED TO SAID SUPPORT MEMBER, A BREECH FOR SAID CARTRIDGE CHAMBER CARRIED BY SAID HANDLE, SAID BREECH ADAPTED TO CLOSE SAID CARTRIDGE CHAMBER WHEN SAID HANDLE IS IN A FIRST POSITION AND ADAPTED TO BE MOVED AWAY FROM SAID CARTRIDGE CHAMBER BY SWINGING SAID HANDLE ABOUT ITS PIVOT AWAY FROM SAID FIRST POSITION, AND FIRING MEANS CARRIED BY SAID HANDLE FOR FIRING A CARTRIDGE IN SAID CARTRIDGE CHAMBER WHEN SAID HANDLE IS IN SAID FIRST POSITION. 